Li Yuanji

Li Yuanji (603-2 July 626) was Prince of Qi and an imperial prince of Tang China under his father, Emperor Gaozu of Tang. He was murdered by his brother, the future Emperor Taizong of Tang, in 626 AD.

Biography
Li Yuanji was born in 603, the son of Emperor Gaozu of Tang and the younger brother of Li Jiancheng and the future Emperor Taizong of Tang. He was immature, holding military exercises with concubines and servants while at Taiyuan; many people died in these staged fights, and Li Yuanji himself was injured. In 626, his older brother, wary of Taizong's growing influence, convinced their father Gaozu to send Li Yuanji to fight the Gokturks instead of sending Taizong, their father's greatest general. This insult was the last straw for Taizong in his sibling rivalry, and he spread a rumor that Jiancheng and Yuanji were engaged in adultery with their father's concubines. As the two brothers returned to Luoyang to answer to these accusations, they were ambushed and killed at Xuanwu Gate by their brother and his subordinates.